Theatres, halls, auditoriums and the like all utilise theatrical lighting or similar for lighting up the stage and other areas of the space. Typically, such lighting is provided by one or more luminaires or other lighting units that are attached to one or more lighting rigs. The lighting rigs are hoisted to the ceiling, and then suspended over the stage and other areas to be lit.
The traditional adjustment methodology of theatre luminaires has been to ‘hang’ or ‘rig’ the luminaires on lighting rigs that have been lowered to the stage floor where they are positioned onto the bar as per the lighting plan, connected to the power circuit and then flown out over the stage to the correct height. Alternatively, the rigs may be permanently fixed to the ceiling. Then, the pan, tilt and focus of each of the lighting units attached to the rig must be adjusted to provide the desired lighting effect. To date, the three adjustable parameters of traditional ‘fixed’ theatre lighting units have been set using separate tools in a time consuming and imprecise manner resulting in a lot of wasted time and frustration. Once the stage setting has been completed, each lighting unit is manually focused, panned and tilted by a technician using a personnel lift or ladder. This is a time consuming process, usually occurring under considerable time pressure and late at night due the constraints of the show change over/set up schedule.
For example, for the pan adjustment, traditional luminaries use a bolt and nut mounted through the suspension hook clamp. The luminaire is panned and then ‘locked off’ in the desired position. This is carried out using a spanner or such like to adjust the nut during which the luminaire is prone to moving. This can result in the whole positioning process having to be repeated.
Likewise, the traditional tilt adjustment is made using a simple lock clamp disc. This is a disc of metal, on the edge of which a bolt head is then screwed over to clamp the luminaire in position. Being a grab/lock clamp only, once loosened off the luminaire tilt is completely free and is subject to swinging down suddenly to the point of equilibrium.
Beam focus is traditionally undertaken by a simple lamp/reflector slide tray moving in relation to the lens. This is moved by the operator using a knob that drives a lead screw. Focus mechanisms with lead screw are slow to set at the desired focus. In an alternative arrangement, the knob directly moves the tray and is then screw tightened against the luminaire housing to secure the position. This action is subject to movement as the screw action clamps against the body.
It would be desirable to have an easier way of adjusting the settings of lighting.